NAV v5.0.5 appears to have a problem in the topology/LLDP portion.  The switch referenced below is a Cisco WS-3750X stack, running 15.2(4)E10.  Referenced devices are [Ubiquiti] APs.  FWIW – the switch does have such things as ARP inspection, DHCP snooping, etc. – enabled.
 
2020-04-13 06:23:35,227 [INFO plugins.lldp.lldpneighbor] [topo switch0.<obscured>] found multiple interface matches for <LLDPNeighbor identified=True netbox=Netbox(id=27, sysname='wifi-b.<obscured>') interfaces=[Interface(id=607, netbox=Netbox(id=27, sysname='wifi-b.<obscured>'), ifname='br0', ifdescr='br0', iftype=6), Interface(id=609, netbox=Netbox(id=27, sysname='wifi-b.<obscured>'), ifname='br0.20', ifdescr='br0.20', iftype=6), Interface(id=589, netbox=Netbox(id=27, sysname='wifi-b.<obscured>'), ifname='eth0', ifdescr='eth0', iftype=6), Interface(id=605, netbox=Netbox(id=27, sysname='wifi-b.<obscured>'), ifname='eth0.20', ifdescr='eth0.20', iftype=6)]>
2020-04-13 06:23:35,229 [INFO plugins.lldp.lldpneighbor] [topo switch0.<obscured>] found multiple interface matches for <LLDPNeighbor identified=True netbox=Netbox(id=28, sysname='wifi-g.<obscured>') interfaces=[Interface(id=610, netbox=Netbox(id=28, sysname='wifi-g.<obscured>'), ifname='br0', ifdescr='br0', iftype=6), Interface(id=611, netbox=Netbox(id=28, sysname='wifi-g.<obscured>'), ifname='br0.20', ifdescr='br0.20', iftype=6), Interface(id=612, netbox=Netbox(id=28, sysname='wifi-g.<obscured>'), ifname='br-trunk', ifdescr='br-trunk', iftype=6), Interface(id=590, netbox=Netbox(id=28, sysname='wifi-g.<obscured>'), ifname='eth0', ifdescr='eth0', iftype=6), Interface(id=608, netbox=Netbox(id=28, sysname='wifi-g.<obscured>'), ifname='eth0.10', ifdescr='eth0.10', iftype=6), Interface(id=606, netbox=Netbox(id=28, sysname='wifi-g.<obscured>'), ifname='eth0.20', ifdescr='eth0.20', iftype=6)]>
2020-04-13 06:23:35,241 [ERROR jobs.jobhandler] [topo switch0.<obscured>] Plugin nav.ipdevpoll.plugins.lldp.LLDP('switch0.<obscured>') reported an unhandled failure
Traceback (most recent call last):
  File "/opt/venvs/nav/lib/python3.7/site-packages/twisted/internet/defer.py", line 500, in errback
    self._startRunCallbacks(fail)
  File "/opt/venvs/nav/lib/python3.7/site-packages/twisted/internet/defer.py", line 567, in _startRunCallbacks
    self._runCallbacks()
  File "/opt/venvs/nav/lib/python3.7/site-packages/twisted/internet/defer.py", line 653, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/opt/venvs/nav/lib/python3.7/site-packages/twisted/internet/defer.py", line 1442, in gotResult
    _inlineCallbacks(r, g, deferred)
--- <exception caught here> ---
  File "/opt/venvs/nav/lib/python3.7/site-packages/twisted/internet/defer.py", line 1384, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "/opt/venvs/nav/lib/python3.7/site-packages/twisted/python/failure.py", line 408, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "/opt/venvs/nav/lib/python3.7/site-packages/nav/ipdevpoll/plugins/lldp.py", line 71, in handle
    yield run_in_thread(self._process_remote)
  File "/opt/venvs/nav/lib/python3.7/site-packages/twisted/python/threadpool.py", line 250, in inContext
    result = inContext.theWork()
  File "/opt/venvs/nav/lib/python3.7/site-packages/twisted/python/threadpool.py", line 266, in <lambda>
    inContext.theWork = lambda: context.call(ctx, func, *args, **kw)
  File "/opt/venvs/nav/lib/python3.7/site-packages/twisted/python/context.py", line 122, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
  File "/opt/venvs/nav/lib/python3.7/site-packages/twisted/python/context.py", line 85, in callWithContext
    return func(*args,**kw)
File "/opt/venvs/nav/lib/python3.7/site-packages/nav/ipdevpoll/db.py", line 100, in _reset
    return func(*args, **kwargs)
  File "/opt/venvs/nav/lib/python3.7/site-packages/nav/ipdevpoll/plugins/lldp.py", line 116, in _process_remote
    neighbors = [LLDPNeighbor(lldp) for lldp in self.remote]
  File "/opt/venvs/nav/lib/python3.7/site-packages/nav/ipdevpoll/plugins/lldp.py", line 116, in <listcomp>
    neighbors = [LLDPNeighbor(lldp) for lldp in self.remote]
  File "/opt/venvs/nav/lib/python3.7/site-packages/nav/ipdevpoll/neighbor.py", line 117, in __init__
    self.identify()
  File "/opt/venvs/nav/lib/python3.7/site-packages/nav/ipdevpoll/neighbor.py", line 121, in identify
    self.interfaces = self._identify_interfaces()
  File "/opt/venvs/nav/lib/python3.7/site-packages/nav/ipdevpoll/plugins/lldp.py", line 222, in _identify_interfaces
    result = lookup(str(portid))
  File "/opt/venvs/nav/lib/python3.7/site-packages/nav/ipdevpoll/plugins/lldp.py", line 248, in _interfaces_from_mac
    return self._interface_query(Q(ifphysaddress=mac))
  File "/opt/venvs/nav/lib/python3.7/site-packages/nav/ipdevpoll/neighbor.py", line 234, in _interface_query
    'id', 'ifname', 'ifdescr', 'iftype').filter(netbox & query):
  File "/opt/venvs/nav/lib/python3.7/site-packages/django/db/models/query.py", line 250, in __iter__
    self._fetch_all()
  File "/opt/venvs/nav/lib/python3.7/site-packages/django/db/models/query.py", line 1121, in _fetch_all
    self._result_cache = list(self._iterable_class(self))
  File "/opt/venvs/nav/lib/python3.7/site-packages/django/db/models/query.py", line 106, in __iter__
    for row in compiler.results_iter(chunked_fetch=self.chunked_fetch):
  File "/opt/venvs/nav/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 841, in results_iter
    results = self.execute_sql(MULTI, chunked_fetch=chunked_fetch)
  File "/opt/venvs/nav/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 899, in execute_sql
    raise original_exception
  File "/opt/venvs/nav/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 889, in execute_sql
    cursor.execute(sql, params)
  File "/opt/venvs/nav/lib/python3.7/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/opt/venvs/nav/lib/python3.7/site-packages/django/db/utils.py", line 94, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/opt/venvs/nav/lib/python3.7/site-packages/django/utils/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/opt/venvs/nav/lib/python3.7/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
django.db.utils.DataError: invalid input syntax for type macaddr: "None"
LINE 1: ..."netboxid" = 26 AND "interface"."ifphysaddress" = 'None') OR...
                                                             ^
 
 
2020-04-13 06:23:35,242 [ERROR jobs.jobhandler] [topo switch0.<obscured>] Job 'topo' for switch0.<obscured> aborted: Job aborted due to plugin failure (cause=DataError('invalid input syntax for type macaddr: "None"\nLINE 1: ..."netboxid" = 26 AND "interface"."ifphysaddress" = \'None\') OR...\n ^\n'))
 
Related: Was running an older version of NAV which appeared (at least via GUI) to have no issue this equipment combination of Cisco and Ubiquiti.  Due to an odd issue, did end up dropping the VM and simply created a new one with latest Debian and latest NAV version, re-populating the equipment and configuration.  Which may have been why certain things came to light?  The Netmap doesn’t appear to be fully populated – suspect that it’s a cascading result of the above error?